A new study in Nature the Journal is giving scientists a clearer picture of how our ancestors became upright walkers. By examining embryos from humans, mice, and a wide range of primates, researchers discovered that although all mammals rely on the same basic genes to build the ilium; the major hip bone; humans use those genes in a very different way. Instead of forming along the spine like it does in other species, the human ilium starts out perpendicular to it. That early shift completely changes how the pelvis grows, ultimately creating the shape and muscle support needed for bipedal movement.
The team also found that the human ilium takes much longer to turn from cartilage into bone compared with the rest of the skeleton. They think this delay emerged as early humans developed larger brains; a slower-forming ilium likely helped widen the birth canal enough to deliver bigger-headed babies. Together, these findings suggest that our evolution didn’t hinge on inventing new genes, but on changing when and where old ones switched on, small developmental tweaks that ended up reshaping how we move and how we’re born.
This study makes it cool to see how small changes in early development helped humans become upright walkers. It’s interesting that the shift in ilium growth also ties into how our species adapted to having bigger brains.
ReplyDeleteThis study is really interesting because it shows that human didn't need new genes to evolved bipedal walking. Its also cool how the different positions of the ilium helped shape our bodies for upright movement.
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